Power is a critical issue in the design and operation of enterprise servers and data centers and is expected to continue to increase in importance due to the ever increasing demands of servers and data centers. Power consumed by cooling equipment (for instance, fans and computer room air conditioners) has also become a significant component in the design and operation of the enterprise servers and data centers. By way of example, the yearly electricity costs for the cooling equipment alone in a large data center (for instance, 30,000 square feet, rated at 10 MW) has been known to run in the millions of dollars.
The same trends in increased power consumption levels are also becoming more applicable at smaller scales, for instance, at the cluster level, or even at an individual server level. More particularly, with increasingly dense compute infrastructures and more powerful processors, the server fans are known to consume increasingly large amounts of power. For instance, the peak power usage by fans of certain blade servers has been found to be as high as 200 W, which comprises about 23% of the typical system power of the blade server.